When I was at school, and a child asked the question ' Please can I go to the toilet, Miss?' The teacher always replied 'I don't know, CAN you?' This dinned it into us that the question should be 'May I?' yes, lots of people say 'could of' nowadays as well. Also 'I fell to sleep' instead of 'I fell asleep.'
I very rarely get annoyed with any of this,as speech is an ever changing thing [we would all be speaking like Geoff Chaucer otherwise ]'Hiya Geoff, how's it going, man?He would just gawp at you wouldn't he?
However, when you do hear somebody speaking intelligently, AND correctly it's always a pleasure.What I really hate, is to hear well educated [men usually] descend into Estuary 'speak', David Cameron, and a LOT of other MP's all do it [Tony Blair used to] saying 'we wanna' 'I'm gonna' etc.We know that they only do it when on camera and it's very annoying.
The other thing is when young men and women put on a sort of quasi ghetto type 'voice' all the innits and so on.This would be ok if they only did this when speaking to their peer groups, but what about when they attend job interviews?